Combined telephone and district alarm system



@No Model.)

I. DRAKE. COMBINED TELEPHONE AND DISTRICT ALARM SYSTEM.

Patented Aug. 4

Wir'wlsea- UNITED STATES PATENT ()rricn.

FLEMON DRAKE, OF SAN FRANCISCO, CALIFORNIA.

COMBINED TELEPHONE AND DISTRICT ALARM SYSTEM.

SPECIFICATION forming part of Letters Patent No. 565,202, dated August4, 1896. Application filed geptember 26, 1894. Serial No. 524,130. (Nomodel.)

To all whom it may concern.-

Be it known that I, FLEMoN DRAKE, a citizen of the United States,residing at San Francisco, in the county of San Francisco and State ofCalifornia, have invented a certain new and useful Improvement in aCombined Telephone and District Alarm System, (Case No. 1,) of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification.

My invention relates to a combined telephone and district alarm system,and its obj ect is the provision of means whereby a district alarmsystem may be associated with a telephone-line to convey to the centralstation a burglar, fire, or other alarm without impairing the use of theline for talking purposes.

My invention in its preferred form comprises a telephone-line extendingfrom a substation to the central station, a local protecting-circuitextending throughout the district to be protected, and an electromagnetor other device, through the agency of which, when theprotecting-circuit is subjected to abnormal conditions, a source ofelectricity is thrown into circuit with the telephone-line to transmitto the central station a current which serves to actuate a bell or otherdevice to sound an alarm.

I will describe my invention more in detail by reference to theaccompanying drawings, in which-- Figure 1 is a diagram illustrating myinvention. Fig. 2 is a similar view showing the telephone cut from lineand the source of electricity thrown into circuit with the centralstation.

Like letters refer to like parts in both figures.

The limbs or a of the telephone-line extend to the central station,where they terminate in the usual spring-jack switches a a andindividual annunciator a In one limb a of the telephone-line is provideda switch-lever 1?, which is adapted to open the circuit through thetelephone set 0. A disk (2 is journaled to rotate about an axis d and issecured to a drum d about which is wound a cord (1 to the end of whichis attached a weight 61 which tends to rotate the disk (1.

The disk is made of insulating material and provided with peripheralprojections e c e 6 adapted as the disk rotates to engage the lever Z)and open the circuit through the telephone set. The opposite projectionsare electrically connected together, as shown, while projections e and eare also electrically connected. Upon the projections e and e normallyrest spring-contacts 71- ha, connected together through the protectivecircuit h, an electromagnet h, and a battery '27. The protective circuitis normally closed, and the magnet h is thus energized to attract itsarmature h mounted upon the end of pivoted lever 705, to therebymaintain the opposite end of said lever in engagement with a pin it onthe disk to prevent the rotation thereof. A spring 77,7 acts to move theend of said lever 7: out of engagement with pin it when magnet h isdenergized. If for any reason the protective circuit be opened, themagnet h is deenergized, and the disk being thus released rotates aboutits axis. The projection 6' comes in contact with switchlever Z) toraise the same and open circuit through the telephone set, as shown inFig. 2. By the time the disk has rotated far enough to raise lever Z)projection c has moved out of contact with spring-contact 7L2, butspring-contact its still remains in contact with projection 6 circuitbeing thus closed from lever b to projection c spring-contact h throughbattery 1 to limb a of the telephone through central station, and backby limb a.

The annunciator of may be employed to receive the signal, or preferablya bell in is included in the strands of a plug and cord adapted to beinserted into one of the springjacks during the night or other time whenthe protective circuit is to be used. To prevent generatorcalling-currents from passing through hell 7c, retardation-coils 7.1 7.5may be included in circuit therewith. lVhen the weight, in descending,strikes the end of the pivoted lever l, the vertical rod Z, pivotedthereto, is raised to engage by its end the notch 19 in the disk toprevent its further rotation. A key art may be provided, adapted to beturned to engage lever 7L and lock the same in position when it isdesired to throw the protective circuit entirely out of operation.

It is evident that my invention is susceptible of numerous embodiments,and I do not therefore desire to limit myself to particulars,

but,

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is-

In a combined telephone and alarm system, the combination with atelephone-line extending from the substation to the central sta tion, ofa telephone set at the substation, a responsive device or indicator atthe central station, a switch included in one limb or side of thetelephone-circuit for opening the circuit through the telephone set, arotating disk carrying projections or contact-terminals arrangedatintervals around the periphery of the disk and adapted to successivelyen gage and open the switch as the disk rotates, said contact-termin alsbeing electrically connected in pairs, a spring or contact-brush adaptedto make electrical contact with said contact-terminals and adapted toengage one of the contact-terminals at the same time that the terminalelectrically connected therewith engages the switch controlling thecontinuity of the circuit through the telephone set, a battery includedin circuit between said spring and the second side or limb of thevtelephoneline, whereby the circuit of the battery may be closed overthe limbs of the telephone-line and through the indicator at the centralstation, a second spring or contactbrush adapted to engage saidcontactterminals, a protective circuit, and an electromagnet includedbetween said second spring and the second side or limb of thetelephone-line, a lock for maintaining the disk against rotation, saidlock being controlled by said electromagnet, the contact-terminals uponwhich said springs normally rest being electrically connected, wherebythe electromagnet, battery and protective circuit are normally includedin alocal circuit and any disturbance of the protective circuit actuatesthe electromagnet to release the rotating disk and transmit a signal tothe central station; substantially as described.

In witness whereof I hereunto subscribe my name this 20th day ofSeptember, A. D.'

FLEMON DRAKE. WVitnesses:

A. E. COCHRAN, THOS-M- OB'R E

